src/lxc/rtnl.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #ifndef __LXC_RTNL_H
   4 #define __LXC_RTNL_H
   5
   6 #include <compiler.h>
   7
   8 /*
   9  * Use this as a good size to allocate route netlink messages
  10  */
  11 #define RTNLMSG_GOOD_SIZE NLMSG_GOOD_SIZE
  12 #define RTNLMSG_DATA(glh) ((void *)(NLMSG_DATA(glh) + RTNL_HDRLEN))
  13
  14 /*
  15  * struct genl_handler : the structure which store the netlink handler
  16  *  and the family number
  17  *
  18  * @nlh: the netlink socket handler
  19  */
  20 struct rtnl_handler {
  21         struct nl_handler nlh;
  22 };
  23
  24 /*
  25  * struct rtnlmsg : the struct containing the route netlink message
  26  *  format
  27  *
  28  * @nlmsghdr: a netlink message header
  29  * @rtnlmsghdr: a route netlink message header pointer
  30  *
  31  */
  32 struct rtnlmsg {
  33         struct nlmsghdr nlmsghdr;
  34 };
  35
  36 /*
  37  * rtnetlink_open : open a route netlink socket
  38  *
  39  * @handler: a struct rtnl_handler pointer
  40  *
  41  * Returns 0 on success, < 0 otherwise
  42  */
  43 __hidden extern int rtnetlink_open(struct rtnl_handler *handler);
  44
  45 /*
  46  * genetlink_close : close a route netlink socket
  47  *
  48  * @handler: the handler of the socket to be closed
  49  */
  50 __hidden extern void rtnetlink_close(struct rtnl_handler *handler);
  51
  52 /*
  53  * rtnetlink_rcv : receive a route netlink socket, it is up
  54  *  to the caller to manage the allocation of the route netlink message
  55  *
  56  * @handler: the handler of the route netlink socket
  57  * @rtnlmsg: the pointer to a route netlink message pre-allocated
  58  *
  59  * Returns 0 on success, < 0 otherwise
  60  */
  61 __hidden extern int rtnetlink_rcv(struct rtnl_handler *handler, struct rtnlmsg *rtnlmsg);
  62
  63 /*
  64  * rtnetlink_send : send a route netlink socket, it is up
  65  *  to the caller to manage the allocation of the route netlink message
  66  *
  67  * @handler: the handler of the route netlink socket
  68  * @rtnlmsg: the pointer to a netlink message pre-allocated
  69  *
  70  * Returns 0 on success, < 0 otherwise
  71  */
  72 __hidden extern int rtnetlink_send(struct rtnl_handler *handler, struct rtnlmsg *rtnlmsg);
  73
  74 __hidden struct genlmsg *genlmsg_alloc(size_t size);
  75
  76 __hidden extern void rtnlmsg_free(struct rtnlmsg *rtnlmsg);
  77
  78 /*
  79  * rtnetlink_transaction : send and receive a route netlink message in one shot
  80  *
  81  * @handler: the handler of the route netlink socket
  82  * @request: a route netlink message containing the request to be sent
  83  * @answer: a pre-allocated route netlink message to receive the response
  84  *
  85  * Returns 0 on success, < 0 otherwise
  86  */
  87 __hidden extern int rtnetlink_transaction(struct rtnl_handler *handler, struct rtnlmsg *request,
  88                                           struct rtnlmsg *answer);
  89
  90 __hidden struct rtnlmsg *rtnlmsg_alloc(size_t size);
  91
  92 #endif /* __LXC_RTNL_H */